Insulated electrical conductor and the like



E. TAYLOR INSULATED ELECTRICAL CONDUCTOR AND THE LIKE June 29 1926.

Original Filed March 11 V Qwbantoz 6M M W35, W1 MM! Patented June 29,1926.

UNITED STATES 1,590,608 PATENT OFFICE.

EDWIN TAYLOR, OF BROOKLYN, NEW YORK, ASSIGNOR TO TAYLOR LABORATORIES, IN0., OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

INSULATED ELECTRICAL CONDUCTOR AND THE LIKE.

Original application filed March 11, 1920, Serial No. 864,980. Dividedand application filed June 17,

1924, Serial no. 720,520. Divided and this application filed March 18,1926. Serial No. 95,802;

My invention relates'to improvements in insulatedelectrical conductorsand the like. The main object of the invention is to provide anelectrical conductor with an improved insulation'of organic material.The invention, however, may also be used for coating other objects thanelectricalvconductors, for example ribbons, sheets, etc. 01' variousmaterials. This application is a division of my prior application Ser.No. 7 20,520 filed June 17, 1924 which in turn is a division of my priorapplication Ser. No. 364,980 filed March 11, 1920.

Further and more specific objects, features and advantages will moreclearly appear from the detail description given below taken inconnection with the accompanying drawing which forms a part of thespecification.

The drawing, partly in vertical section, illustrates more or lessdiagrammatically an apparatus adapted to put the main features of theimprovements in one form.

According to my invention in its preferred form, I insulate or coat theconductor or other body with a layer of cellulose. I preferably do thisby making a suitable solution of cellulose, applying a layer of this tothe wire conductor or other body and removing the solvent constituentsfrom cellulose, leaving a homogeneous integrally continuous layer ofcellulose on the body. I preferably remove the solvent constituents byelectrolytic action. For this purpose I preferably dissolve the .organicmaterial such as cellulosic material in a solution of zinc chloride orasolution of hydrated cupric oxide in concentrated ammonia. By suchsolution of the cellulose in zinc chloride or the cuproammonia thecellulose is converted from the cellular or fibrous condition to a,colloidal state. I preferably use a solution which is relativelyconcentrated and thick, and apply a suitable layer thereof to the bodyto be coated and then subject the cellulose solution on the body toelectrolysis whereby the cellulose is' deposited more solidly upon'thebody to be coated which may serve as the anode, and the copper or zincas the case maybe, is deposited on a cathode, the'chlorine or ammoniabeing given ofi in gaseous form. Both the gas so given off, as well asthe metal deposited on the cathode,'may be recovered for .re-use.

Referring to the drawing which illustrates an apparatus adapted for usein coating or covering rods or filaments of cellulose as well oppositewall of the tank 10 is a hollow fitting or nozzle 43, provided with abore substantially the size of the objectto be coated and placed centralwith the bore of nozzle 12.

The nozzle 12 projects through the wall of a second tank 20, of anydesired length, and

' fitted at its further wall with a'stuifing box having a centralperforation 47, approximately of the diameter of the coated rod or wire.A vent pipe 33 is placed at the top of tank 20, for the removal bysuction of gases released or generated during operation.

Below the level of the liquid in tank 20, and central with nozzle12 andstufiing box 47, is suspended a tubular electrode 37 split lengthwise tofacilitate removal,. and provided with electric connections 38, the tubebe ng a cathode while in useuBeyond tank 20 and communicating withit-bythe stuffing box 47, is a third tank 50 containing a roller 48 atits further end. V

The object to be coated, for instance a wlre 46 on a reel 45, is ledthrough nozzles 43 and 12, through gu de piece 44, orifice 4, electrode37, stuffing box 47, under roller 48, and to a reel 51, situated outsideof tank 50 and so driven that it may place the wire under enough tensionto draw it from the reel and through the apparatus. Tank 10 is nowfilled with a viscous, concentrated monia, or inthe case of silk innickel-ammonia alone or in a mixture of both cupro.

' solution of organic material such as cotton or silk dissolved-forexample in cupro-aman electric current is passed through the wire 46 bymeans of a contact shoe 28, and

a conductor 29, connected to the positive pole of a source ofelectricity. The wire 46 while passing through the tubular electrode 37,becomes an anode and 37 a cathode. cellulose issuing between the wall ofthe orifice 4 and the centrally located-wire 46 is caused to flow at aslower speed than the wire and is drawn or stretched thereon in auniform coating of any desired thickness the flotation effect of thebath materially preventing flow of the viscous solution after eavingnozzle 12 and before the cellulose has been finally deposited on wire 46by the travel of the coated wire through the oath means of the currentpassingduring passes through the -stufling box 47 filling the borethereof and so preventing the water in tank from mixing with the acidliquid in 20 or vice versa. The coated wire 49 is now well washed duringpassage through tank 50 passes under under ide-roll 48, and to reel 51,it now being rea y for drying or for further desired operations. It isobvious that in place of one wire or rod passing through orifice 4, anynumber of wires maybe passed in parallel each bin separated from itsneighbor by coating 0 cellulose, etc., and the whole enclosed in a likecoating of any desired thickness, Furthermore the nozzles and apparatusmay be so constructed and placed that a twisted or v cable effect may.be imparted to the wires during coating.

The above process after drying, etc., results in a tough, elastic,transparent coating which is substantially impermeable to oil and of anythicknessor color, etc., desired,

firmly adherent to the wire and of a-high' di-electric-strength. Thecoating resulting ing the "covered wire as it, leaves t 50 throughsuccessive apparatus of the. e kind, the coated wire still wet passi inat. a nozzle similar to 43 but of larger re to from the above described.process is substantially pure cellulose and the cellulose ispractically. uncombined, that is, 'it is not combined with esters orother radicals to form compounds such as xanthates, nitrates, and thehke. Successive coats of the same or different material may be given byassaccommodate the increased diameter.

' In the application of thislproc'ess and its modifications as appliedto isilk advantage may be taken of the fact that silk will dissolve innickel ammonia solution, while cotton will notyalthough cupro-aminoniadis- The,

solves both. Mixed silk and cotton waste goods, etc., may be separatedand'rendered of increased commercial value by first'treating the mixedmaterial with nickel-ammonia whereb the silk is dissolved and removedfrom t e cotton by filtration.

The cotton may now be dissolved in cupro-ammonla and 7 As to the processin general the utmost care' sliould be exercised to avoid all dustanddirt. The solutions must be carefully filtered and dirt kept outafterward. 'All the apparatus should be closed in wherever possible. Thewater employed for making up the solutions should be distilled or at anyrate contain a minimum of mineral salts and should be free from carbonicacid gas if a fine filament or a perfectly transparent product isdesired.

The stren h of the acid water must also be kept wit in reasonable limitsalthough this is eas on account of the large volume in the tanlicompared to the amount circu-- slowly. This acid water should also ekept free-from grosser impurities and from CO I prefer to use nitricacid as its ultimate product under electrolysis is always amcount of themany variations of the generalprocess, A direct current is preferable;.a pulsating current in one direction gives good results but takesatlonger time. The problem is an electro-chem cal one andthe rate ofdeposition of both cellulose and metal s a function of the amperagerather than of voltage. .For instance, in the electrolysis of cellulosedissolved in cupro-ammoma, I have used currents of 110 volts and acurrent densityv of amp. per sq. inch of anode surface, while almost thesame result may be obtained with 1.8 .volts and of an amp. per sq. inch,although the time required is longer. .In geneiah'only enough 'lated,changes in concentration takin place amperage should be carriedto securea reasonably adherent deposit on the cathode,.

of I the metallic .solu t1 on c-onsttu1uent pinilo ed.- If thecurrent'zafef isnn y ra se it spongy deposit .of fif'tal ifp'rms which s apt tofall into the bath, adhere to the material being treated and otherwisecause trouble, while at the same timethe bath overheatsand more currentpasses than is required. Contrary to this a heavy amper age favors thedeposition of cellulose. For cathodes a metal similar to the one used inthe solvent, copper, nickel, zinc, etc, should be employed. With alittle attention to the amperage passed all these metals me be depositedin a somewhat spongy'condi-- tion and while adhering well to thecathode, may be easily scraped therefrom in a condi-. tion to be readilyre-dissolved for the preparation of new solutions.

, For dissolving the organic'material, cellulose, silk, etc., if thesolution is to be an ammoniacal one, I prefer to saturate 'ammoniawater, free from. carbonate of ammonia, etc.,- withhydrated cupric ornickel oxides The solutions are filtered through fibrous,intro-cellulose, cooled to about 40 F. and saturated with the materialto .be dis-' solved in suitable mixin machines. The

amount of material d1ssolved' depends largely upon the fibre etc. usedvarying some-whatlwith each diflerent qualit or grade of the same kindof material. ome' raw cottons for. instance willcompletely dissolve in,the proportion of l lb. cotton to 20 lbs. of cupra, while with othervarieties,

' l lb. cotton to 35 lbs. solution is the best that can be done. Whenusing zinc chloride,

I employ a saturated solution of'the C. P. salt indistilled water, thesesolutions. being-- even more sensitive to im urities than theammoniaones and" more ifiicult to handle and recover;

.. After solution is complete the viscous mass is allowed ,to standfor-aboutj24 hours,

during which" time-it becomes m'uch more fluid and may be forced througha filter by means of pressure. A-fine 'sandbed on top ofa layer ofnitro-cotton, which in turn 1s supported by a fine wire screen is quitesatisfactory.- When desired the solutions are now concentrated bycentrifugal action.

' At this stage. other ingred entsmay be added to the" more orless-fluid solution. .For ;instance,'if a saturated solution of cotton,or

other cellulose in cupro-ammonia is employed itis evident that if morecellulose,

say in a fibrous but rather finely divided state be. added, this latteraddition will be' practically unaffected by the solution but it willincrease the viscosity of the mass, necessitate a h1gher pressure toforce it through the nozzles or-dies. and will materially reduce theshrinkage or'drying, the result be-.

sire to be limited to such details and forms,

since many changes .and modifications may be made and the" improvementsembodied in widely difierent forms without departing from the spirit andsee c thereof in their broader as ects; hence desire to. cover all formscoming within the language or scope of any one or'more oftheiap endedclaims.

. What I claim as new and, 'esir'e to secure by Letters Patent, is: p

1. An insulated electrical conductor ,com-

prising. aconductin" wire with an insulating coating of su stantiall'ynon-fibrous, structureless and uncombined cellulose thereon, saidcoating being substantially transparent, homogeneous and substantiallycon- .tinuous throughout and substantially impermeable to oil.

2; A body having thereon-acoatingof substantially pure cellulose, thecellulose being substantially noncellular and structuretially continuouscoatingsubstantially impermeable to oil.

In testimony whereof I have signed my name to this specification.

EDWIN TAYLOR.

less and uncombined and forming a substan' Y

